This ash cloud height and distance graphic is the output of a mathematical model of volcanic ash transport in the atmosphere (PUFF, UAF Geophysical Institute).

This model shows expected movement of an ash cloud in the atmosphere for actual eruptions.

KVERT produces this graphic when a volcanic eruption began or occurs, in order to provide an eruptive forecast of airspace likely to be affected. During an eruption, KVERT will update the forecast with actual observations (eruption duration, plume height and distance) as they become available.

Colored dots represent the estimated height of the top of the ash cloud, in feet above sea level, as it drifts downwind. [Change the color bar legend to “Height of top of ash cloud”]

This graphic does not show ashfall deposition on the ground. Note that it is possible for ash clouds to move overhead with little or no fallout on the ground.